Testing device



FIG. 1 is a top perspective view of a testing device with its cap on;

FIG. 2 is a side view thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a bottom view thereof;

FIG. 5 is a left view thereof;

FIG. 6 is a right view thereof; and,

FIG. 7 is a top perspective view thereof with its cap off.

The broken lines in the figures depict portions of the testing device that form no part of the claimed design. 

CLAIM The ornamental design for a testing device, as shown and described. 